| Component | Langflow |
| Severity | critical (CVSS 9.8) |
| CVSS vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| Published (NVD) | 2026-03-20 |
| Last modified | 2026-06-17 |
| Affected versions | langflow < 1.8.2 |
| Fixed in | 1.8.2 |
| Weakness | CWE-94CWE-95CWE-306 |
| CISA KEV | listed 2026-03-25 |
NVD description
Langflow is a tool for building and deploying AI-powered agents and workflows. In versions prior to 1.9.0, the POST /api/v1/build_public_tmp/{flow_id}/flow endpoint allows building public flows without requiring authentication. When the optional data parameter is supplied, the endpoint uses attacker-controlled flow data (containing arbitrary Python code in node definitions) instead of the stored flow data from the database. This code is passed to exec() with zero sandboxing, resulting in unauthenticated remote code execution. This is distinct from CVE-2025-3248, which fixed /api/v1/validate/code by adding authentication. The build_public_tmp endpoint is designed to be unauthenticated (for public flows) but incorrectly accepts attacker-supplied flow data containing arbitrary executable code. This issue has been fixed in version 1.9.0.
CISA required action
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
What to do
- Upgrade Langflow to
1.8.2or later. - Do not expose the component's API or UI to the internet without authentication in front of it.
- It is exploited in the wild: treat unpatched hosts as compromised, rotate the secrets they hold and review their logs.
Sources
- NVD: CVE-2026-33017
- https://github.com/langflow-ai/langflow/security/advisories/GHSA-vwmf-pq79-vjvx
- https://github.com/langflow-ai/langflow/commit/73b6612e3ef25fdae0a752d75b0fabd47328d4f0
- https://github.com/langflow-ai/langflow/releases/tag/1.8.2
- https://medium.com/@aviral23/cve-2026-33017-how-i-found-an-unauthenticated-rce-in-langflow-by-reading-the-code-they-already-dc96cdce5896
- https://github.com/advisories/GHSA-rvqx-wpfh-mfx7
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-33017
- https://www.sysdig.com/blog/cve-2026-33017-how-attackers-compromised-langflow-ai-pipelines-in-20-hours
Read more
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